Still available.
Celestron Owners, please note:
This model of bob's Knobs are specifically for a CPC1100.
This may not and probably doesn't, fit other C11 models.
1. C11 Std: To fit all Celestron 11 inch (28 cm) f/10 SCT versions (metal or carbon fiber tube) with flat secondary housing and standard 6-32 collimation screw threads (not for CPC 1100). Most C11's prior to 2006.
2. C11 Met: to fit Celestron 11 inch (28 cm) f/10 SCT versions with flat or Trifid Fastar secondary housing and metric M3 screw threads (CPC 1100).
3. C11fst: To fit all Celestron 11 inch (28 cm) f/10 SCT versions (metal or carbon fiber tube) with "Trifid" rotary cover Fastar secondary housing and standard collimation screw threads. These knobs will also fit the C11 with Starizona Hyperstar.
The ones for sale here are type 2. above.
If in doubt (and to be sure) please see the Bobs Knobs site:
at
http://www.bobsknobs.com/Celestron/Celestron.htm
where they have photos of the different scope types because I think
you need to have the right thread type and the right screw length.